// 布尔类型
let isDone: boolean = true;
let isDone2: boolean = false;

console.log(isDone);
console.log(isDone2);

//数值类型
let num: number=10;
let num2 : number = Number(1);

console.log(num);
console.log(num2);

//字符串类型
let truename: string = "张三";
let nickname : string = "李四";
//模板字符串
let age : number = 13;
let sentence: string = `名字: ${truename}, 今年${age}岁`;

console.log(truename);
console.log(nickname);
console.log(age);
console.log(sentence);

//空值

let u :undefined = undefined;
let n : null =null; 

// let u: number = undefined;
// u=0;
